Certainly the petrol cars are.
So, I can't find anything specific on the CX-5 but I found this:
http://www.consumerreports.org/car-reliability/car-brands-reliability-how-they-stack-up/
Mazda is ranked in the top group of consumer reports brand reliability. And one of only a few companies where all the cars are recommended.
So, I guess they are pretty reliable overall.